Supporting research – integration of innovative reactor physics methods into transient criticality modelling: Towards a Next Generation FETCH

Overview of new methods integration into FETCH Robust, adaptive RT methods  Adaptivity in space, energy, angle and time (full adaptivity)  Robust, sub-grid scale methods for numerical stability  Fast hierarchical solvers in space and angle Robust, CFD methods for systems with shocks  New schemes for modelling shocks  Towards an unstructured mesh FETCH capability Uncertainty Propagation Methods  SFEM for RT  SFEM for multiphase CFD  Coupled modelling SFEM

Fully adaptive RT methods tailoring themselves to the physics of the problem (to a given resolution scale). Fully adaptive, fast, robust RT framework (with appropriate adjoint error metrics) Adaptive spatial meshing Anisotropic adaptivity in angle Adaptivity in energyAdaptivity in time Hierarchical solvers Sub-grid scale stabilisation

Shock wave capturing, unstructured Multi-phase flow Modelling Multi-phase flow modelling is currently structured mesh based with a pressure corrected shock capturing scheme New developments to include unstructured capability as well as numerically “robust” Riemann based shock capturing schemes. Results from a expanding shock wave in a postulated waste repository scenario

Uncertainty Methods for Improved Engineering design Methods to improve the design of complex engineering systems subject to multiple uncertainties Uncertainties during engineering design can affect the system Safety Reliability Performance Cost Risk

Multiphysics SFEM uncertainty methods New approach for modelling multiple uncertainties using stochastic finite elements Fluid dynamics processes Nuclear Processes Input uncertainties Probability distributions of outputs Power, fission rate, temperatures, pressures

Funding of these initiatives Five year RAEng Fellowship in Uncertainty Methods Eng Doc Student on uncertainty in nuclear data in collaboration with Nexia/Serco Assurance – student David Perry EPSRC student underpinning the group’s work on shock wave modelling, unstructured multiphase flow – work towards an unstructured mesh FETCH capability – student Justin Hadi KNOO funded EPSRC student on SFEM for single phase flow - student Andrew Hagues Part time Imperial PRI/AWE PhD student on radiation methods - student Simon Merton Imperial/Rolls-Royce Eng Doc on radiation methods - student Christopher Baker Imperial/Rolls-Royce Eng Doc on thermal-hydraulics - student Emily Julian